Metal worker's lung: spatial association with Mycobacterium avium.

BACKGROUND: Outbreaks of hypersensitivity pneumonitis (HP) are not uncommon in workplaces where metal working fluid (MWF) is used to facilitate metal turning. Inhalation of microbe-contaminated MWF has been assumed to be the cause, but previous investigations have failed to establish a spatial relationship between a contaminated source and an outbreak. OBJECTIVES: After an outbreak of five cases of HP in a UK factory, we carried out blinded, molecular-based microbiological investigation of MWF samples in order to identify potential links between specific microbial taxa and machines in the outbreak zone. METHODS: Custom-quantitative PCR assays, microscopy and phylogenetic analyses were performed on blinded MWF samples to quantify microbial burden and identify potential aetiological agents of HP in metal workers. MEASUREMENTS AND MAIN RESULTS: MWF from machines fed by a central sump, but not those with an isolated supply, was contaminated by mycobacteria. The factory sump and a single linked machine at the centre of the outbreak zone, known to be the workstation of the index cases, had very high levels of detectable organisms. Phylogenetic placement of mycobacterial taxonomic marker genes generated from these samples indicated that the contaminating organisms were closely related to Mycobacterium avium. CONCLUSIONS: We describe, for the first time, a close spatial relationship between the abundance of a mycobacterium-like organism, most probably M. avium, and a localised outbreak of MWF-associated HP. The further development of sequence-based analytic techniques should assist in the prevention of this important occupational disease.

Histology atlas of the developing mouse hepatobiliary system with emphasis on embryonic days 9.5-18.5.

Animal model phenotyping, in utero exposure toxicity studies, and investigation into causes of embryonic, fetal, or perinatal deaths have required pathologists to recognize and diagnose developmental disorders in spontaneous and engineered mouse models of disease. In mammals, the liver is the main site of hematopoiesis during fetal development, has endocrine and exocrine functions important for maintaining homeostasis in fetal and adult life; and performs other functions including waste detoxification, production and removal of glucose, glycogen storage, triglyceride and fatty acid processing, and serum protein production. Due to its role in many critical functions, alterations in the size, morphology, or function(s) of the liver often lead to embryonic lethality. Many publications and websites describe individual aspects of hepatobiliary development at defined stages. However, no single resource provides a detailed histological evaluation of H&E-stained sections of the developing murine liver and biliary systems using high-magnification and high-resolution color images. The work herein provides a histology atlas of hepatobiliary development between embryonic days 9.5-18.5. Although the focus of this work is normal hepatobiliary development, common defects in liver development are also described as a reference for pathologists who may be asked to phenotype mice with congenital, inherited, or treatment-related hepatobiliary defects. Authors' note: All digital images can be viewed online at https://niehsimagesepl-inc.com with the username "ToxPathLiver" and the password "embryolivers."

Connective tissue growth factor (CTGF) inactivation leads to defects in islet cell lineage allocation and beta-cell proliferation during embryogenesis.

The factors necessary for normal pancreatic islet morphogenesis have not been well characterized. Here we report that connective tissue growth factor (CTGF) is involved in the establishment of normal islet endocrine cell ratio and architecture. CTGF is a secreted protein known to modulate several growth factor-signaling pathways including TGF-beta, BMP, and Wnt. Although its role in pancreatic diseases such as pancreatitis and pancreatic cancer are well documented, a role for CTGF in normal pancreas development and function has heretofore not been examined. Using a lacZ-tagged CTGF allele, we describe for the first time the expression pattern of CTGF in the developing pancreas and the requirement of CTGF for normal islet morphogenesis and embryonic beta-cell proliferation. CTGF is highly expressed in pancreatic ductal epithelium and vascular endothelium, as well as at lower levels in developing insulin(+) cells, but becomes down-regulated in beta-cells soon after birth. Pancreata from CTGF null embryos have an increase in glucagon(+) cells with a concomitant decrease in insulin(+) cells, and show defects in islet morphogenesis. Loss of CTGF also results in a dramatic decrease in beta-cell proliferation at late gestation. Unlike CTGF null embryos, CTGF heterozygotes survive past birth and exhibit a range of islet phenotypes, including an intermingling of islet cell types, increased number of glucagon(+) cells, and beta-cell hypertrophy.

pdx-1 function is specifically required in embryonic beta cells to generate appropriate numbers of endocrine cell types and maintain glucose homeostasis.

The pdx1 gene is essential for pancreatic organogenesis in humans and mice; pdx1 mutations have been identified in human diabetic patients. Specific inactivation of pdx1 in adult beta cells revealed that this gene is required for maintenance of mature beta cell function. In the following study, a Cre-lox strategy was used to remove pdx1 function specifically from embryonic beta cells beginning at late-gestation, prior to islet formation. Animals in which pdx1 is lost in insulin-producing cells during embryogenesis had elevated blood glucose levels at birth and were overtly diabetic by weaning. Neonatal and adult mutant islets showed a dramatic reduction in the number of insulin(+) cells and an increase in both glucagon(+) and somatostatin(+) cells. Lineage tracing revealed that excess glucagon(+) and somatostatin(+) cells did not arise by interconversion of endocrine cell types. Examination of mutant islets revealed a decrease in proliferation of insulin-producing cells just before birth and a concomitant increase in proliferation of glucagon-producing cells. We propose that pdx1 is required for proliferation and function of the beta cells generated at late gestation, and that one function of normal beta cells is to inhibit the proliferation of other islet cell types, resulting in the appropriate numbers of the different endocrine cell types.

Transforming the future of health together: The Learning Health Systems Consensus Action Plan.

The Learning Health Community is an emergent global multistakeholder grassroots incipient movement bonded together by a set of consensus Core Values Underlying a National-Scale Person-Centered Continuous Learning Health System developed at the 2012 Learning Health System (LHS) Summit. The Learning Health Community's Second LHS Summit was convened on December 8 to 9, 2016 building upon LHS efforts taking shape in order to achieve consensus on actions that, if taken, will advance LHSs and the LHS vision from what remain appealing concepts to a working reality for improving the health of individuals and populations globally. An iterative half-year collaborative revision process following the Second LHS Summit led to the development of the Learning Health Systems Consensus Action Plan.

Maintenance of hepatic nuclear factor 6 in postnatal islets impairs terminal differentiation and function of beta-cells.

The Onecut homeodomain transcription factor hepatic nuclear factor 6 (Hnf6) is necessary for proper development of islet beta-cells. Hnf6 is initially expressed throughout the pancreatic epithelium but is downregulated in endocrine cells at late gestation and is not expressed in postnatal islets. Transgenic mice in which Hnf6 expression is maintained in postnatal islets (pdx1(PB)Hnf6) show overt diabetes and impaired glucose-stimulated insulin secretion (GSIS) at weaning. We now define the mechanism whereby maintenance of Hnf6 expression postnatally leads to beta-cell dysfunction. We provide evidence that continued expression of Hnf6 impairs GSIS by altering insulin granule biosynthesis, resulting in a reduced response to secretagogues. Sustained expression of Hnf6 also results in downregulation of the beta-cell-specific transcription factor MafA and a decrease in total pancreatic insulin. These results suggest that downregulation of Hnf6 expression in beta-cells during development is essential to achieve a mature, glucose-responsive beta-cell.

Patient-centered drug development and the Learning Health System.

Patient-centered drug development (PCDD) is a shift in the way that drugs are developed, systematically incorporating patient participation in all stages of medicines development. The more the research sector understands the needs and values of patients, the more effective and efficient it can be in bringing meaningful drugs and evidence to patients and providers. In this paper, we describe PCDD, provide examples of PCDD work across the phases of drug development, and discuss the challenges to making PCDD systematic. We describe how the developing Learning Health System will enable PCCD: we believe that the Learning Health System will address PCDD barriers by connecting stakeholders, enabling the more efficient flow of data, information, and evidence in the health ecosystem, and by providing governance for the connected ecosystem.

Prevention of Tracheostomy-Related Hospital-Acquired Pressure Ulcers.

Objective To determine if standardization of perioperative tracheostomy care procedures decreased the incidence of hospital-acquired tracheostomy-related pressure ulcers. Methods All patients at least 18 years old who underwent placement of a tracheostomy tube in the operating room from July 1, 2014, through June 30, 2015, were cared for postoperatively through an institutionally adopted quality improvement protocol. This included 4 elements: (1) placement of a hydrocolloid dressing underneath the tracheostomy flange in the postoperative period, (2) removal of plate sutures within 7 days of the tracheostomy procedure, (3) placement of a polyurethane foam dressing after suture removal, and (4) neutral positioning of the head. One year after the bundle was initiated, a retrospective analysis was performed to compare the percentage of tracheostomy patients who developed pressure ulcers versus the preintervention period. Results The incidence of tracheostomy-related pressure ulcers decreased from 20 of 183 tracheostomies (10.93%) prior to use of the standardized protocol to 2 of 155 tracheostomies (1.29%). Chi-square analysis showed a significant difference between the groups, with a P value of .0003. Discussion Adoption of this care bundle at our institution resulted in a significant reduction in the incidence of hospital-acquired tracheostomy-related pressure ulcers. The impact of any single intervention within our protocol was not assessed and could be an area of further investigation. Implications for Practice Adoption of a standardized posttracheostomy care bundle at the institution level may result in the improved care of patients with tracheostomies and specifically may reduce the incidence of pressure ulcers.

Creating and using real-world evidence to answer questions about clinical effectiveness.

New forms of evidence are needed to complement evidence generated from randomised controlled trials (RCTs). Real-World Evidence (RWE) is a potential new form of evidence, but remains undefined. This paper sets to fill that gap by defining RWE as the output from a rigorous research process which: (1) includes a clear a priori statement of a hypothesis to be tested or research question to be answered; (2) defines the data sources that will be used and critically appraises their strengths and weaknesses; and (3) applies appropriate methods, including advanced analytics. These elements should be set out in advance of the study commencing, ideally in a published protocol.The strengths of RWE studies are that they are more inclusive than RCTs and can enable an evidence base to be developed around real-world effectiveness and to start to address the complications of managing other real-world problems such as multimorbidity. Computerised medical record systems and big data provide a rich source of data for RWE studies. However, guidance is needed to help assess the rigour of RWE studies so that the strength of recommendations based on their output can be determined. Additionally, RWE advanced analytics methods need better categorisation and validation.We predict that the core role of RCTs will shift towards assessing safety and achieving regulatory compliance. RWE studies, notwithstanding their limitations, may become established as the best vehicle to assess efficacy.

Gestational diabetes mellitus resulting from impaired beta-cell compensation in the absence of FoxM1, a novel downstream effector of placental lactogen.

OBJECTIVE: The objectives of the study were to determine whether the cell cycle transcription factor, FoxM1, is required for glucose homeostasis and beta-cell mass expansion in maternal islets during pregnancy and whether FoxM1 is essential for placental lactogen (PL)-induced beta-cell proliferation. RESEARCH DESIGN AND METHODS: beta-Cell mass, beta-cell proliferation, and glucose homeostasis were assessed in virgin, pregnant, and postpartum mice with a pancreas-wide Foxm1 deletion (FoxM1(Deltapanc)). Wild-type islets were cultured with or without PL and examined for Foxm1 induction. Transgenic mice overexpressing PL in beta-cells were bred with FoxM1(Deltapanc) mice, and beta-cell proliferation was examined. RESULTS: Foxm1 was upregulated in maternal islets during pregnancy. In contrast to controls, beta-cell proliferation did not increase in pregnant FoxM1(Deltapanc) females. Mutant islets showed increased Menin and nuclear p27. FoxM1(Deltapanc) females developed gestational diabetes mellitus as pregnancy progressed. After parturition, euglycemia was restored in FoxM1(Deltapanc) females, but islet size was significantly reduced. Strikingly, beta-cell mass was normal in postpartum FoxM1(Deltapanc) pancreata due to a combination of increased beta-cell size and islet neogenesis. Evidence for neogenesis included increased number of endocrine clusters, increased proportion of smaller islets, and increased neurogenin 3 or insulin expression in cells adjacent to ducts. PL induced Foxm1 expression in cultured islets, and FoxM1 was essential for PL-mediated increases in beta-cell proliferation in vivo. CONCLUSIONS: FoxM1 is essential for beta-cell compensation during pregnancy. In the absence of increased beta-cell proliferation, neogenesis is induced in postpartum FoxM1(Deltapanc) pancreata. Our results suggest that FoxM1 functions downstream of PL to mediate its effects on beta-cell proliferation.

Gene expression profiling of a mouse model of pancreatic islet dysmorphogenesis.

BACKGROUND: In the past decade, several transcription factors critical for pancreas organogenesis have been identified. Despite this success, many of the factors necessary for proper islet morphogenesis and function remain uncharacterized. Previous studies have shown that transgenic over-expression of the transcription factor Hnf6 specifically in the pancreatic endocrine cell lineage resulted in disruptions in islet morphogenesis, including dysfunctional endocrine cell sorting, increased individual islet size, increased number of peripheral endocrine cell types, and failure of islets to migrate away from the ductal epithelium. The mechanisms whereby maintained Hnf6 causes defects in islet morphogenesis have yet to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: We exploited the dysmorphic islets in Hnf6 transgenic animals as a tool to identify factors important for islet morphogenesis. Genome-wide microarray analysis was used to identify differences in the gene expression profiles of late gestation and early postnatal total pancreas tissue from wild type and Hnf6 transgenic animals. Here we report the identification of genes with an altered expression in Hnf6 transgenic animals and highlight factors with potential importance in islet morphogenesis. Importantly, gene products involved in cell adhesion, cell migration, ECM remodeling and proliferation were found to be altered in Hnf6 transgenic pancreata, revealing specific candidates that can now be analyzed directly for their role in these processes during islet development. CONCLUSIONS/SIGNIFICANCE: This study provides a unique dataset that can act as a starting point for other investigators to explore the role of the identified genes in pancreatogenesis, islet morphogenesis and mature beta cell function.